1. Field of the Invention
This invention relates generally to an automatic paper roll pasting apparatus, and more particularly to an automatic paper roll pasting apparatus for rotary presses, which is web-fed and accept a continuous strip of paper from paper rolls to print thereon, constructed so that a paper roll which is now feeding a continuous strip of paper, or a paper web, to the rotary press and approaching to the end thereof with the progress of printing is automatically pasted to a new paper roll without interrupting the operation of the rotary press.
2. Description of the Prior Art
The rotary press is usually used to continuously print newwpaper and other printing material on a continuous strip of paper, or paper web, supplied from a paper roll. To ensure continuous printing in this type of printing machine, a running paper web currently being fed from a paper roll must be automatically pasted to a new paper roll when the residual length of the existing paper roll runs short as printing proceeds. To effect the automatic pasting of paper rolls, the peripheral speed (revolution) of a new paper roll being pasted is caused to agree with the revolution of the running paper web, and then the ends of both paper webs are pasted, for example, by contact-bonding adhesive layers applied in advance on both ends. In order to measure the speed of a paper web now being fed (running paper web) to the rotary press and the peripheral speed of a new paper roll to be pasted so as to cause the revolutions of both to agree with each other, a roller has heretofore been employed, which is brought into contact with the outermost periphery of the rotating paper roll being pasted to measure the peripheral speed of the new paper roll. In such an arrangement, however, the roller for measuring the revolution of the new paper roll being pasted tends to vibrate due to irregularities which would have been produced on the outermost periphery of the paper roll for some reasons, making it difficult to accurately measure the peripheral speed of the new paper roll. SUMMARY OF THE INVENTION
This invention is intended to overcome the above problem.
It is the first object of this invention to provide an automatic paper roll pasting apparatus having a means for accurately and quickly measuring the peripheral speed of a rotating new paper roll being pasted without being affected by irregularities produced on the outer periphery of the paper roll.
It is the second object of this invention to provide an automatic paper roll pasting apparatus having a paper roll revolution control means for calculating a revolution signal by correlating the speed of a paper web now being fed with a value relating to the diameter of a new paper roll being pasted, and controlling the revolution of the new paper roll by comparing the calculated revolution signal with the revolution signal of the new paper roll being pasted.